The OSPF Hello protocol performs which of the following tasks? (Choose two.)（）
- AIt provides dynamic neighbor discovery.
- BIt detects unreachable neighbors in 90 second intervals.
- CIt maintains neighbor relationships.
- DIt negotiates correctness parameters between neighboring interfaces.
- EIt uses timers to elect the router with the fastest links as the designated router.
- FIt broadcasts hello packets throughout the internetwork to discover all routers that are running OSPF